Treatment of peat.



T. mew. TREATMENT OF FEAT,

A'PPLICATIQH FILED .MYL 191 yammm Dec, 25,1917,

3 SHEETS-SHEET a.

; miioims IQQIVBIQJOFZ constrains,

. To all whom iii-may concern:

a: .Bef it known that L THOMAS. Riser, a

':''subject of the King of Great Britain and Ireland, and residing at 61 Loreburn street,

-Dumfries, Scotland, have inventedcertain nc'vv and useful Improvements in and Re- .-lat1ng rte-the Treatment of Peat, of which cthe. following is a specification.

. This invention relates to the treatment of peat by processes having .fOr their object the removal with greater ease of associated liquid ...matter therefrom, such removal se cured under the influence of heat with or without other agency; It has particular reference to those cases where the nature of z-the peat or the treatment adopted, or both, is

such thatthe reaction is brought about at lower-temperatures than usual for instance not far, ifat. all, above 100 C., and even in some instances. appreciably below this temperature.

7 The particular object of the invention is to effect savings in the heat consumption of the process.

According to this invention when effecting heattreatment of peat transfer of heat from I hottreated Wet peat or from hot liquid removed therefromis elfected by condensing water vapor-obtained from one or both of the former in such manner as to yield heat to 4 raw peat awaiting treatment, this being preferablyeiiected byuninterruptedly transferring heat in. this manner from a continu- 'ouslylflowing mass ofthe treated material .to one of raw. material, said water vapor being carried from onematerialto the other byfa circulating current of moisture-carrymg ,gas '01 bein generated by release of pressure or, production of a partial vacuum,

or in. other similar. manner. In order to effect further econom es according to the resent invention, moisture- J ,ladengasesresu ting from the drying of the treated peat,'-for example, (see British Pat- .entNo. 24748 of 1911), or cooling water from gas cooling -operations .in byproduct Specification of Letters Patent.

- Application filed may 7, 1914. Serial fie. $37,664.

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'scorLann, ass sicoa re wsrcsanonrzme LIMITED, or nonnciaaneraivn.

TREATMENT or rear.

Patented nee. as, 1911.

cuperation oi heat by gas circulated between 1i treated and untreated material,

Figs. 1 1*. and 1 showing details thereof; in

Fig. 2 an elevation of a modification'in ing gas between hot press eiiluent and raw peat; and in F 1g 3 a form in which recuperation is effected by vaporizing water from hot treated. peat by reduction of superincumbent pressure and introduction of this raw peat.

Themethod about to be described is par ticularly appiicable where only a low maximum working temperature is maintained in the heat treatment process as a consequence of entirely or partially avoiding the pulping and destruction of the fibers usually re-. sorted to and where as a further consequence of the conditions required in continuous working it becomes important that the handling shall be of such a character as at most to involve mixing and not disintegration to any substantial extent. The method is, however, also applicable to those other cases of heat treatment where the maximum temperature to be reached is not a high one or even in the latter case if it be combined with regeneration methods such as have been previously proposed or are hereinafter discussed, having for their result to reduce the material in an economical manner to a temperature approaching that at which filtration can be undertaken. It constitutes a companion to application Serial Number.

180,648,; filed Julyli, 1917, which has-been divided therefrom.

In the form. shown in Figs. 1; 1 and 1 transfer of heat from hot to cool material is effected by a circulating current of gas, for instance air, which may be only in part returned after parting with its heat, or may be very largely if not wholly replaced by fresh quantities liberated from the peat by the heating which it undergoes.

The hot peat which has undergone heat treatment ina stagewhere evaporation is prevented enters at 1 into a casing 2, within which a drum slowly rotates, carrying the peat over with it to the far side of the casing whence it is discharged at 3, passing to a similar device i, which it leaves at 5. A current of gas from the fan 6, however, en-

which regeneration is effected by circulat- Y vapor into the peat upon the drum, cools it by taking up moisture, and then passes by the pipe 8 to the second casing 2 (wherein the operation 1 5 is repeated) and which casing it leaves at I the point 9. In this Way, peat is by passing through the casings 2 and a cooled to the desired degree gas current becomes more or less saturated ture, and passes by the pipe to the devices 11 and 12, in which the converse operation takes place, the gas giving up its heat by condensationof its water vapor in the peat, and returning to the fan by the pipe 13, while the peat leaves the apparatus at the point 1 L, when its heat treatment under conditions preventing evaporation can be completed as is deemed most expedient. It will 2}; be understood that numbers of heating and 5 cooling elements employed may-be varied according to the circumstances. In Figs. 1

' and 1, which how one of these devices in greater detail in sectional elevation and-in plan respectively, is indicated the casing 2, within which revolves with the shaft 15 the drinn 16, the necessary seal against loss of vacuum or pressure, according to circumstances being insured by a packing ring 17 so under influence of springs 18 (see Fig. 1).

A wall 19 prevents direct flow through the apparatus, and an appropriate liquid seal, indicated by Way of example at 20, is also provided. p

In some instances, instead of or in addition to the method last described, the heat may be obtained by passing the gas current into contact-with hotefiiuent for which pur-' pose instead of a device of the character last ccdescribed, a gas washer of more or less ordinary character may be employed.

Thus, in Fig. 2 is shown a Washer '21 through which hot effluent flows, and in which it is dispersed by paddles 22, the gas current flowing in a. contrary direction, and passing by the pipe-23 to a pair of devices of the character already described, which are arranged in series, the gas ciu'rent (which eventually returns by the pipe 24 to the Washer) heating raw peat entering at 25, and passing from the heaters to a plunger feeding'device 26, and thence to the vessel,

27, from which after heat treatment under conditions preventing evaporation the peat finally passes to the presses.

' Such a manner of effecting the regeneration is useful where the heat of cooling water from gas cooling plant of by-product recover-y or other gasifiers is available and it as forms a more economical way of recovering heat than the present practice of employing the heated coolingw'ater to saturate as faras possible the blast for the gas producer which is often objectionable owing to the as limited temperature oifg 'thelargevolumeof before filtration, while 1 the a with water vapor at an elevated tempera-- cooling water and the small quantity of air required for the producer. If hot peat efiiu-l ent be available at a relatively high temperature, say near100 (1., and be employed for saturation of the blast,'it becomes possible to obtain much higher temperatures, so

that in certain circumstances the need for additional steam may be quite eliminated. 1 Thus by using gas cooling Water for heating peat, andv peat effluent for saturating the blast, substantial over-all economies become possible. Again, where the later stages of the'drying of the peat are effected by heating in direct contact with gases (see for instance British PatentsNos. 17610 and 24748 should be near their saturation temperature,

for which purpose if the Washing which they are usually subjected to for removal of residual peat dust has not already done so sufficiently, they may be suitably Water or air cooled.

Where in the heat treatment according to any of the methods indicated regeneration of heat from a material at a temperature above the atmospheric boiling point is desired, this may in certain cases with advantage be effected by releasing the pressure in one or a number of stages, and then recovering the heat of this steam by admixture of the same with cooler material, or by surface heating in appropriate heat exchanging the production of the partial vacuum and other energylosses to a large extentreappearing as heat in the evacuated products and being thus economized.

Such an arrangement is indicated in Fig. 3, in which peat introduced into the pipe 28 by the feeding device 29 enters. a mixer, 30, the equivalent ofthe vessel 27 (Fig. 2) pass. ing thence through the pipe 31 provided with steam nozzles 32 to the vessel. 33, wherein the, heat treatment under conditions pre- I25 venting evaporation is completed. The peat is forced from this vessel by the feeding de-- vice through a pipe 34, connected-to a vessel 35,also provided with a. pipe 36 sealed at its base by a bend 37 the pipes 34 and 36,130

- of peat by the pipe 40.

- Having now described my invention, what I claim as new and desire to secure by Let ters Patent is 1. A method of economizing heat in the treatment of peat effected by raising its temperature under pressure sufiicient to prevent evaporation, consisting in transmitting heat from the product of the treatment to the uncarrying matter which circulates between and comes directly into contact with both the heat rejecting product of the treatment and the heat absorbing untreated material. 2; A method of economizing. heat in the treatment of peat effected by raising its temperature under pressure suflicient to prevent evaporation, consisting in circulating a current of gaseous matter such as air so thatit comes in direct contact with the hot products of the treatment to extract heat therefrom and also in direct contact with the cooler peat about to be treated to impart heat thereto.

treatment of peat effected by raising its temperature under pressure sufficient to prevent evaporation consisting in extracting heat from the product of the treatment by means of a circulating body of heat'carryi-ng matter, extracting a further quantity of heat of lower degree from liquid expressed from the treated material by means of a circulating body of heat carrying matter and imparting at separate stages to the material about to be treated the heat thus extracted.

4. A method of economizing heat in the treatment of peat effected by raising its temperature under pressure sufficient to prevent evaporation, consisting in extracting heat from the product of the treatment by means of vapor generated upon a reduction of pressure, extracting a further quantity of heat of lower degree from said product by means of a circulating body of heat carrying matter such as air brought in direct contact therewith and imparting atseparate stages to the material about to be treated the heat thus extracted.

5. A method of economizing heat in the treatment of peat effected by raising its temperature under pressure sufficient to prevent evaporation, consisting in extracting heat 3. A method of economizi-ng heat in the from the product of the treatment by means of vapor generated upon a reduction of pressure, extracting a further quantity of heat of lower degree from liquid expressed from the treated material by means of a circulating body of heatcarrying matter such as air and imparting at separate stages to the material about to be treated the heat thus extracted.

6. A method of economizing heat in thetreatment of peat effected by raising its temperature under pressure sufficient to prevent evaporatlon, consisting 1n extracting heat from the product of the treatment by means treated material by the intermediary of heat",

of vapor generated upon a reduction of pressure, thereafter extracting heat of lower dcgTee from said product by means of a circulating body of heat carrying mattersuch as air brought in direct contact therewith, extracting a further quantity of heat of still lower degree from liquid expressed from the treated material by means of a circulating body of heat carrying matter and imparting at separate stages to the material about to be treated the heat thus extracted.

7. A method of rendering the water 'of peat more freely expressible,consisting in heating the peat without evaporation thereof in order to destroy its water binding properties, expressing liquid from peat thus treated, and circulating a gas in contact with the resulting effluent and untreated. peat in order to preheat the latter.

' 8. A method of economizing heat in the treatment of peat in tubular heating a'ppa rat-us, through which it is continuously passed while being heated to destroy its water binding properties, consisting in dewatering the treated peat while 'hot,'and circulating a gas between the warm effluent and untreated peat inorder to preheat the latter.

9. A method of economizing heat in the treatment of peat in tubular heating appav Witnesses 'BERTRAM H; llilATTHE-WS, C. S. DEALTRY. 

